Typically, integrated circuitry is interfaced to other circuitry through input and output receivers and drivers ("IORDs"), which are logic portions of the integrated circuitry. The IORDs are respectively connected to other logic portions (e.g. registers, multiplexers, arrays). Moreover, the IORDs are respectively connected to terminal pads ("terminals") of the integrated circuitry. These terminal pads are connected to a package in which the integrated circuitry is encapsulated. More particularly, the terminal pads include a top level metal layer connected to the package.
Commonly, designs of the integrated circuitry and of the package are done largely in parallel. More particularly, the designs are done after defining interfaces between the integrated circuitry and the package, yet before completion of either design. Connections between the integrated circuitry and the package are finalized before completion of either design.
In order to avoid greatly constraining the locations of the IORDs' respectively connected logic portions within the integrated circuitry, conventionally the IORDs are positioned on the periphery of the integrated circuitry. Accordingly, the integrated circuitry is designed so that a necessary border is reserved around its periphery for the IORDs. In this manner, connections between the integrated circuitry and the package are more readily finalized before completion of either design, while allowing designs of the integrated circuitry and of the package to be done largely in parallel.
Nevertheless, such previous techniques have shortcomings. For example, by positioning the IORDs on the periphery of the integrated circuitry, the IORDs are frequently more physically remote from their respectively connected logic portions within the integrated circuitry. Moreover, more silicon area can be used, and less efficient use is made of metal layers, in order to position the IORDs on the periphery of the integrated circuitry. Also, performance of the integrated circuitry can be degraded by positioning the IORDs on the periphery of the integrated circuitry.
Thus, a need has arisen for a method and structure for connecting to integrated circuitry, in which IORDs are not necessarily positioned on the periphery of the integrated circuitry. Also, a need has arisen for a method and structure for connecting to integrated circuitry, in which IORDs are more physically proximate to their respectively connected logic portions within the integrated circuitry, relative to previous techniques. Further, a need has arisen for a method and structure for connecting to integrated circuitry, in which less silicon area is used, and more efficient use is made of metal layers, in order to locate the IORDs on the integrated circuitry, relative to previous techniques. Moreover, a need has arisen for a method and structure for connecting to integrated circuitry, in which performance of the integrated circuitry is improved relative to previous techniques. Yet another need has arisen for a method and structure for connecting to integrated circuitry, in which portions of the integrated circuitry have a greater placement flexibility relative to previous techniques, even after interfaces are defined between the integrated circuitry and the package.